Index: src/OFString.h
==================================================================
--- src/OFString.h
+++ src/OFString.h
@@ -560,10 +560,18 @@
  * \param string The string to append
  * \return A new autoreleased OFString with the specified string appended
  */
 - (OFString*)stringByAppendingString: (OFString*)string;
 
+/**
+ * Creates a new string by prepending another string.
+ *
+ * \param string The string to prepend
+ * \return A new autoreleased OFString with the specified string prepended
+ */
+- (OFString*)stringByPrependingString: (OFString*)string;
+
 /**
  * \return The string in uppercase
  */
 - (OFString*)uppercaseString;
 

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -1404,10 +1404,26 @@
 	OFMutableString *new;
 
 	new = [OFMutableString stringWithString: self];
 	[new appendString: string_];
 
+	/*
+	 * Class swizzle the string to be immutable. We declared the return type
+	 * to be OFString*, so it can't be modified anyway. But not swizzling it
+	 * would create a real copy each time -[copy] is called.
+	 */
+	new->isa = [OFString class];
+	return new;
+}
+
+- (OFString*)stringByPrependingString: (OFString*)string_
+{
+	OFMutableString *new;
+
+	new = [OFMutableString stringWithString: string_];
+	[new appendString: self];
+
 	/*
 	 * Class swizzle the string to be immutable. We declared the return type
 	 * to be OFString*, so it can't be modified anyway. But not swizzling it
 	 * would create a real copy each time -[copy] is called.
 	 */

Index: tests/OFStringTests.m
==================================================================
--- tests/OFStringTests.m
+++ tests/OFStringTests.m
@@ -241,10 +241,13 @@
 			       toIndex: 0])
 
 	TEST(@"-[stringByAppendingString:]",
 	    [[@"foo" stringByAppendingString: @"bar"] isEqual: @"foobar"])
 
+	TEST(@"-[stringByPrependingString:]",
+	    [[@"foo" stringByPrependingString: @"bar"] isEqual: @"barfoo"])
+
 	TEST(@"-[hasPrefix:]", [@"foobar" hasPrefix: @"foo"] &&
 	    ![@"foobar" hasPrefix: @"foobar0"])
 
 	TEST(@"-[hasSuffix:]", [@"foobar" hasSuffix: @"bar"] &&
 	    ![@"foobar" hasSuffix: @"foobar0"])